How Long Is an ESA Letter Good For?

Nothing in federal law stamps a use-by date on an assistance-animal letter. Pages that tell you a letter “is valid for one year” are describing how these documents are usually written, not quoting a rule anyone can point to. That is the accurate answer, and on its own it is also useless — because what a renter really wants to know is whether the letter sitting in a drawer will still do its job. That question has very little to do with expiry and a great deal to do with who wrote it, when, and on what basis.

The deadline that does not exist

The federal regulations covering assistance animals in housing say nothing about time. The reasonable accommodation duty at 24 C.F.R. § 100.204(a) makes it unlawful to refuse an accommodation in rules, policies, practices or services where it may be necessary to give a person with a handicap an equal opportunity to use and enjoy a dwelling. The definition the request runs on, at § 100.201, turns on an impairment substantially limiting a major life activity. Section 100.202(c) restricts what a housing provider may ask about a disability.

Read all three and you will find no validity period, no renewal schedule, and no mechanism by which a document becomes void on a calendar date. Anyone who tells you a letter “expired” is describing something the law does not do.

There is also no memo left to argue about. The federal sub-regulatory guidance that property managers used to quote on documentation was pulled: the withdrawal notice appears at 91 FR 17291 and took effect on September 17, 2025. The regulations survived it untouched, which is why they are the only text worth citing in this argument.

So why do letters carry dates at all?

Because a letter is not a licence or a permit. It is a professional’s written judgment about a person, made on a particular day, with their licence number attached to it. A clinician who signs one is saying something about the person in front of them at that moment — not issuing a status that attaches to you permanently.

That is why the issue date is on the page, and why many professionals name a period they are prepared to stand behind. It is a statement of professional scope, not a legal countdown. The distinction matters, because it explains why an old letter is weaker without being invalid.

Reliability is the actual test

Housing providers are not checking your letter against an expiry schedule. Where a disability or the need for the animal is not obvious, they are asking whether the information in front of them is trustworthy enough to act on. Two states have written that test into statute in terms that make the point unmistakable.

Pennsylvania’s Assistance and Service Animal Integrity Act, Act 118 of 2018, permits a provider to request documentation only where the disability or the disability-related need is not readily apparent or known. Section 3(b) then says what the documentation has to be: in writing, reliable, based on direct knowledge, and describing the disability-related need for the animal.

Sit with the phrase “based on direct knowledge.” It is not asking when the letter was signed. It is asking whether the person who signed it knows you. A document from a professional who assessed you properly and still has your file is easy to defend on that standard. A document from a name you encountered once, on a website, four years ago, is not — and its weakness on the day it was written does not improve with age. Full detail sits on the Pennsylvania guide.

Florida legislated the same instinct differently

Fla. Stat. § 760.27 tells a housing provider what supporting information it may accept. Subsection (2)(b)4. contemplates information from a health care practitioner or a telehealth provider, and then attaches a condition to out-of-state signatures: the practitioner counts only where they have provided in-person care or services to the tenant on at least one occasion, have personal knowledge of the disability, and are acting within their scope of practice.

Notice what Florida did not do. It did not set a shelf life. It regulated the relationship instead — which is the legislature reaching the same conclusion by a different route. The Florida guide covers the rest of § 760.27, including the limits it places on what a landlord may demand.

California is worth knowing about for the same reason. Cal. Health & Safety Code § 122318, added by AB 468, requires a licensed professional to hold a client relationship of at least 30 days and to complete a clinical evaluation before issuing the letter — again a rule about substance rather than shelf life. Details are on the California guide.

The moments a letter genuinely needs revisiting

None of the following is a legal expiry. All of them are situations where a current letter does work an old one cannot.

A new tenancy. Your previous landlord’s decision does not travel with you. The next housing provider evaluates the request from scratch, with no knowledge of you and no reason to treat a three-year-old document generously.

A move across a state line. The federal floor follows you; the state layer does not. If the destination legislates who may write the letter, a signature from your old state may not satisfy it. Our guide to moving to a new state with an ESA sets out which rules change at the border.

A change in your circumstances. A different animal, a materially different clinical picture, or a new treating professional all mean the old letter describes a situation that no longer exists. It is not false; it is simply about someone you no longer are.

A relationship that has lapsed. If you have not seen the signer in years, or the practice has closed, or the licence has moved states, the document has quietly lost the thing that gave it weight. This is the most common version, and the easiest to miss, because the paper looks exactly the same.

A dispute. If a provider has questioned your documentation, a fresh assessment answers the objection far faster than an argument about whether the old one still counts. What a provider may and may not challenge is covered in what to do when a landlord calls your letter fake.

A new request is not a renewal

This distinction is worth holding onto, because landlords blur it and so do a lot of articles.

A landlord who tells a sitting tenant that an approved accommodation lapses annually is inventing a rule. But a landlord you have never rented from, considering a request you have never made to them, is not renewing anything — they are deciding for the first time, and the strength of what you hand them is entirely within your control.

What does not make an old letter stronger

There is a whole product category aimed at people in this position, and none of it helps. An identification card, a vest, a numbered certificate or a listing in an online registry adds nothing to a document whose problem is that no one currently knows you. Florida says as much in statute: an emotional support animal registration of any kind obtained from the internet is not by itself sufficient to establish a disability or a disability-related need. Buying one does not refresh a letter. It signals that you went looking for a substitute for an assessment.

A two-minute self-audit

Take the letter out and check whether it still says something true about you today:

1. Is the issue date recent enough that the description of your situation still fits?
2. Is the signer someone you could realistically contact this week?
3. Are they still licensed, still practising, and still reachable at the contact details printed on the page?
4. Are they licensed where you now live, or do they have a documented in-person history with you?
5. Does the letter state a disability and a disability-related need for the animal, without disclosing your diagnosis?
6. Was there a real evaluation behind it — a conversation, not a form?

A “no” on items two, three or six is the real answer to “how long is my letter good for.” It was already weak; time only made that visible.

If the answer is that you need a fresh one

Start with any clinician already treating you, since they have the direct knowledge the statutes are asking about and the assessment is usually shorter than a first evaluation with a stranger. If you have no current provider, the process is the same one described in our guide to getting a legitimate ESA letter: a licensed professional, a genuine evaluation, and a signed document naming their licence.

Budget for it as an occasional cost of maintaining a defensible position, in the same way you would keep any other document about your circumstances current.

The bottom line

No federal rule gives an ESA letter an expiry date, and no landlord can manufacture one. What they can do — and what the statutes in several states now expressly invite them to do — is weigh whether the documentation in front of them is reliable and grounded in real knowledge of the person who handed it over.

On that test, the strongest thing you can give a housing provider is simple: a current letter from a licensed professional who actually assessed you, whose licence you can name, and who would recognise your file if the phone rang.